336 Appendix to Proceedings 



lars. The cell resembles an amphora or flask lying on its side, 

 having the neck bent more or less sharply upwards, and dila- 

 ted into a trumpet-shaped mouth. Its colour is dark sea- 

 green, in the larger specimens nearly opaque. The trans- 

 parent green animalcule is long and cylindrical, as in other 

 genera of the family Ophrydina, and is attached by its pos- 

 terior extremity to the bottom of the tube. Its anterior ex- 

 tremity is crowned by a rotatory organ, the form of which is 

 unique among the Protozoa, but which is the homomorph of 

 the hippocrepian type, occurring in Alcyonella and others 

 amongst the Polyzoa, and in Phoronis amongst the Annelida. 

 This organ, when seen in front, and erect (fig. 2), appears like 

 a narrow horse-shoe ; whilst from the side the anterior ex- 

 tremity of the animalcule bears a resemblance to the head and 

 ears of a hare. A thick muscular (?) band passes round the 

 border of the horse-shoe, and forms the basis of a wreath of 

 long vibratile cilia (fig. 3), the motion of which produces the 

 optical illusion of moving cogs or teeth. The whole surface 

 of the body and rotatory organ is seen (under a power of 300 

 diam.) to be striated with fine lines, which bear cilia in most 

 active motion. The gullet (?) in the first specimen taken, 

 was, in every case examined, a shallow sac placed within the 

 bend of the horse-shoe and between the ciliary bands ; but in 

 the last batch of specimens, which were of much larger size, 

 it invariably passed deeply within the body as a tapering 

 canal, in which the motion of large cilia could be clearly de- 

 tected. 



Although both colonies were exceedingly numerous, and 

 lived a considerable time with me, I was never able to dis- 

 cover their mode of increase. They were never seen double — 

 " two single gentleman rolled into one" — as the convivial Va- 

 gincola appears to. be when undergoing multiplication. Two 

 Lagotias, indeed, keeping house in the same bottle would 

 doubtless lead a most unhappy life. The single tenant is an 

 ill-conditioned and restless fellow, constantly rotating this 

 way and that, and wagging his long ears ; and, when sitting 

 for his portrait, assuming as many changes of character as 

 Charles Matthews himself. 



The colour of the body of L. viridis is not caused by an 



